Power supply for tetherless workstations

ABSTRACT

A tetherless workstation is provided having a rechargeable battery power supply installed therein for supplying electrical power to equipment associated with the workstation. The battery power supply includes a diagnostics interface for monitoring an indication of at least the battery charge level and for outputting that indication together with a unique identifier stored within the power supply for transmission over a wireless communications interface. A monitoring apparatus is also provided to monitor the operational status of tetherless workstations using indications output by their respective power supplies, for logging usage of workstations and for generating reports on their operational status, including predictions relating to their operational status.

This application is the US national phase of international applicationPCT/GB02/01094 filed Mar. 11, 2002 which designated the U.S.

BACKGOUND

1. Technical Field

The present invention relates generally to power management in flexibleoffice arrangements and, in particular, to power supplies for use intetherless workstations capable of supporting a range of electroniccommunications facilities in a tetherless manner, and to facilities forthe management of such power supplies.

2. Related Art

Modern office accommodation is required to support ever increasingdemands for flexible working arrangements. Whereas in the past, mostoffice workers generally occupied or at least retained the use of a deskfull time, during office hours, an increasing proportion of people nowwork partly from home, using standard office accommodation on an ad hocbasis for particular tasks. For such people, it is generallyuneconomical to reserve desk space for their exclusive but only parttime use. In response to this, so called “hot desking” arrangements havebeen devised whereby particular desks or whole sections of office spaceare set aside to be booked on an ad hoc basis by individuals needingdesk space for only short periods, from an hour or so to several days ata time. Each such desk offers a standard package of communicationfacilities, including a telephone, and a personal computer, or at leasta port for connecting a portable laptop computer, with access to networkservices such as local printing, intranet/internet access and e-mail.

However, while such hot-desk arrangements are relatively easy to provideand to manage on an individual basis where the office furniture andcommunications facilities are otherwise conventional, there isincreasing demand for flexible office arrangements whereby a team ofusers may set up a customised office arrangement for a short period oftime according to their particular needs or preferences. To help addressthis need, the Applicant has provided a range of moveable officefurniture under the futurespace™ brand, including a moveable deskproviding a standard range of communications facilities operating in anentirely tetherless manner. A rechargeable battery power supply unit(PSU) is installed in the desk, providing power for a low voltage flatpanel display, wireless LAN interface, cordless DECT-standard telephoneand other powered items that a user might require, e.g. desk lamp,mobile phone charger. A wireless keyboard and mouse are also providedfor communicating with an optionally installed personal computer usingradio or infra-red signalling. The battery PSU includes an inverter forproviding mains power within the desk, the battery having sufficientcapacity to power the desk's computing and communications facilitiesunder typical loading for at least a working day. At the end of eachworking day, a procedure is enacted for moving the desks to a pointwhere they can be connected to the office mains outlet for over-nightrecharging. The connection itself can be by means of a conventional plugand socket or inductive coupling.

So called “tetherless” desks, such as that above, can be easily movedinto place to form customised office arrangements. With relatively smallnumber of such desks in a given area, keeping the PSU batteries chargedand the desks operational is quite straightforward. However, where alarge number of such desks are in use in a given office or building,management of the desk population is a more complex undertaking. Inparticular, differing demands on a desk's power supply, limited batterylife (expressed as the number of charge-discharge cycles), call for andprovide opportunities for a more effective management process.

BRIEF SUMMARY

According to a first aspect of the present invention, there is provideda battery power supply, comprising:

a battery pack;

an inlet for an externally supplied charging current;

a store for storing a unique identifier for said battery power supply;

a diagnostics interface arranged to monitor and to output at least anindication of the level of charge in said battery pack, and to outputsaid unique identifier stored in said store; and

a wireless communications interface for transmitting an output from saiddiagnostics interface.

A battery power supply according to this first aspect may be readilyused as a source of electrical power in a number of different tetherlessapplications.

According to a second aspect of the present invention, there is provideda tetherless workstation having installed therein a battery power supplyaccording to said first aspect.

According to a third aspect of the present invention there is providedan apparatus, for monitoring a plurality of battery power suppliesaccording to said first aspect of the present invention, comprising:

a wireless communications interface for receiving signals output fromthe diagnostics interface of a battery power supply; and

means, responsive to data received at said wireless communicationsinterface, to generate reports relating to the operational status ofsaid battery power supplies.

According to a fourth aspect of the present invention there is providedan apparatus, for monitoring a plurality of tetherless workstationsaccording to said second aspect of the present invention, comprising:

a wireless communications interface for receiving signals output fromthe diagnostics interface of a battery power supply;

a store for storing, in respect of each of said plurality of tetherlessworkstations, a unique workstation identifier and the unique identifierof a battery power supply installed therein; and

means, responsive to data received at said wireless communicationsinterface and to data stored in said store, for generating reportsrelating to the operational status of said tetherless workstations.

According to preferred embodiments of an apparatus according to saidfourth aspect, there are provided alternatively or in combination: meansfor storing a usage log in respect of at least one of said workstations;analysis means for analysing data received at said wirelesscommunications interface and data stored in said usage log and forgenerating predictions relating to the operational status of saidtetherless workstations; means for identifying users of said tetherlessworkstations and including in said usage log data identifying respectiveusers; and analysis means arranged to generate predictions relating tothe operational status of at least one of said workstations in respectof a particular user.

According to a fifth aspect of the present invention there is provided aflexible office arrangement comprising a plurality of tetherlessworkstations according said second aspect, and an apparatus formonitoring said plurality of workstations according to said fourthaspect.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will now be described indetail, by way of example only, with reference to the accompanyingdrawings of which:

FIG. 1 is a diagram showing a known design for a tetherless deskarrangement;

FIG. 2 is a diagram showing the features of a battery power supply unitaccording to a preferred embodiment of the present invention;

FIG. 3 is a diagram showing features of a flexible office arrangementaccording to a preferred embodiment of the present invention; and

FIG. 4 is a diagram showing the functional features of a desk managementsystem according a preferred embodiments of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring to FIG. 1, a known tetherless desk arrangement 1 is shown asmade available under the Applicant's futurespace™ brand, suitable foruse in implementing preferred embodiments of the present invention. Thearrangement 1 comprises a cabinet 5 mounted on castors 10. The cabinet 5carries a low voltage flat panel display 15 and is provided with a worksurface 20 and a slidably mounted door 25 (shown approximately twothirds open) giving access to the interior of the cabinet 5. Theinterior of the cabinet 5 is fitted with shelves 30, a battery powersupply unit (PSU) 35, an optional personal computer (PC) 40 linked tothe display 15 and one or more mains power outlets 45 supplied from thePSU 35 for connecting electrical equipment, including PC 40, required bya user of the desk arrangement 1. Also provided in the desk arrangement1 is a separately moveable table 50 providing a separate work surface onwhich may be placed a wireless keyboard 55 and mouse 60 for use with theoptional PC 40.

In the known tetherless desk arrangement of FIG. 1, the PSU 35 comprisesa battery charger, a battery pack and an inverter to provide a mainsvoltage alternating current output for use in powering electricalequipment such as the PC 40, or other equipment required by a user ofthe desk arrangement 1. The PSU 35 may also provide a battery chargelevel indicator mounted on the PSU itself or extended by a cable to aposition on the surface 20 of the cabinet 5. Battery charge level may beindicated for example by an easily read voltmeter or a simplecolour-coded electro-luminescent device. Users are then able to respondto a reading of a low battery charge level if such were to occur duringworking hours, and so avoid problems of a power failure, perhaps movingthe desk to a position for connection to a mains outlet or to thevicinity of an inductive loop for recharging, and continuing work onanother desk. Similarly, at the end of each working day, each desk maybe quickly inspected for low battery charge level and moved to aposition for over-night recharging.

There will now be described, according to a preferred embodiment of thepresent invention, with reference to FIG. 2, an improved power supplyunit (PSU) and associated equipment to facilitate improved monitoringand management of tetherless desk arrangements. The PSU to be describedmay be installed in tetherless desk arrangements similar to that shownin FIG. 1 and is particularly suited to the monitoring and management ofa large number of such tetherless desks, or to those distributed over alarge office space or over a number of floors.

Referring to FIG. 2, a diagram is provided to show in particular thefunctional features of a preferred PSU 200. The PSU 200 comprises abattery pack 205 connected, via a relay switch 210, to an inverter 215for producing a mains voltage electrical power output. A battery charger220, connectable to a mains supply for recharging purposes, is alsoconnected to the battery pack 205 within the PSU 200. The PSU 200 isalso provided with a PSU diagnostics interface 225 to provide accessfrom outside the PSU 200 to various diagnostic parameters useful formonitoring the status and use of the PSU. In particular, the diagnosticsinterface 225 is linked to: the battery charger 220 for receivingindications relating to use of the charger 220; a battery monitor 230providing an indication of the battery pack voltage and current output;the relay switch 210, enabling power output from the PSU 200 to beenabled or disabled via the PSU diagnostics interface 225; and to astore 235 for storing a unique identifier for the PSU 200.

To enable diagnostic parameters to be read from outside the PSU 200, anyone of a number of possible techniques may be used to read or displaydata accessible from the diagnostics interface 225. In the particularembodiment shown in FIG. 2, the diagnostics interface 225 may be linkedby one or both of a cable 240 leading to a diagnostics display panel245, and a wireless telemetry transmitter/receiver 250. The displaypanel 245 may be mounted either on the PSU housing itself or it may bemounted in a visible position for example on the surface 20 of a deskcabinet 5, as in FIG. 1, having the PSU 200 installed therein, the cable240 being extended as necessary. The diagnostic display panel 245 mayalternatively be linked to the diagnostics interface 225 by one of anumber of different short-range wireless techniques should the deskdesign preclude the possibility or desirability of using a cable 240.

As an alternative to the use of a display panel 245, use may be made ofa display screen mounted on the desk having the PSU 200 installedtherein, such as the flat panel display 15 shown in FIG. 1, to displaydiagnostics data output by the diagnostics interface 225. For example, avideo overlay device may be installed within the PSU 200 or within thedesk to receive an output from the diagnostics interface 225 and tosuperimpose an image on the display 15 when in use, either permanentlyor periodically for only a few moments at a time. In another method, theinterface 225 may be linked to a serial port on a PC provided in thedesk, and a computer program may be installed to run on the PC toreceive input from the interface 225 and to display diagnostic data in awindow as part of the windows environment running on the PC.

Use of a wireless telemetry transmitter/receiver 250 enables diagnosticinformation for the PSU 200 to be relayed to a remote location.Preferably, at the remote location, a more or less sophisticatedmonitoring apparatus 270 is provided comprising a wireless telemetrytransmitter/receiver 260 linked to a PSU monitor 265. The PSU monitor265 may be a simple display device or a PC running a computer program togather output of the diagnostic interfaces 225 of a number of PSUs 200for processing, storage analysis and/or display. Each transmission ofdiagnostic parameter data from diagnostic interface 225, via telemetrytransmitter/receiver 250, includes the PSU identifier (235) to enablethe source of the parameter data to be determined at the remotemonitoring apparatus 270. Any combination of one or more of theabove-mentioned diagnostic parameters may be transmitted continuouslyor, preferably, at predetermined time intervals to minimise the loadingon the battery pack 205.

Other known methods of wireless communication may be used to relaydiagnostic information from the PSU 200 to a remote location. Forexample, if the desk is provided with a wireless LAN interface, then thePSU 200 may be allocated an IP address and communication to and from thediagnostics interface 225 may be achieved over the LAN in a conventionalway, in addition to or as an alternative to the wireless telemetrytransmitter 250. However, if the LAN is likely to be out of service fromtime to time, continued availability of an independent wirelesstechnique specifically associated with the PSU 200 itself, such as thetelemetry interface 250, is to be preferred.

The diagnostics interface 225 may be provided with access to anycombination of one or more of the diagnostic parameters mentioned above.For example, a simple battery charge level indication may be received atthe interface 225 from the battery monitor 230, represented by a voltagemeasurement of the battery pack 205, and the battery charge levelrepresented by that voltage measurement may be displayed as a threecolour graded charge level indication on the display panel 245 or at theremote monitoring apparatus 270. A more complete diagnostic informationdisplay at the panel 245 or remote apparatus 270 may comprise chargerstatus, battery charge level, battery output current, PSU on/off statusand PSU identifier (235). The panel 245 or remote apparatus 270 mayinclude an ON/OFF switch, linked via the diagnostics interface 225 tothe relay switch 210, to enable or disable the output of mains poweroutput from the PSU 200.

Preferably, any module operating within the PSU 200 and requiring asource of electrical power may obtain that power from the battery pack205. It is therefore desirable that the consumption of electrical powerby such modules be minimised, for example by periodic rather thancontinuous operation.

There will now be described, with reference to FIG. 3, a preferredarrangement for a so-called “flexible office” using tetherless desks ofa design similar to those of FIG. 1, each having a PSU 200 installedtherein. The arrangement shown in FIG. 3 is somewhat simplified incomparison with a typical real implementation, there being only threetetherless desks shown together with a simple office LAN arrangement. Inpractice, there are likely to be many more desks being used, amplyjustifying deployment of a desk management system to be described inmore detail later.

Referring to FIG. 3, three tetherless desks 300 are shown, in dottedoutline (for simplification, comprising only the cabinet portions 5 ofthe desk arrangements 1 of FIG. 1), one of which is explicitly shown tobe containing a PSU 200 and a PC 305 connected to a mains outlet socket310 supplied with mains electricity from the PSU 200. The PC 305 isprovided with a wireless LAN interface 315 to enable communication witha locally provided LAN 320, which may itself be totally wireless, via acorresponding wireless LAN interface 325. The LAN 320 includes a LANserver 330 to provide local data storage and access to commonapplication programs. In practice a LAN 320 also provides users of thetetherless desks 300 with access to local printing facilities, e-mailand Internet/intranet access, none of which are shown in FIG. 3 by wayof simplification.

Also shown linked to the LAN 320 in FIG. 3 is a desk management system335 comprising a desk management computer 340, a display terminal 345and a wireless telemetry transmitter/receiver 350. Apparatus andfunctions of the desk management system 335 will be described in moredetail below. However, as with the simple PSU monitoring apparatus 270of FIG. 2, the desk management system is arranged to receive, viawireless telemetry transmitter/receiver 350, diagnostic data transmittedby the PSUs 200 mounted in the desks 300, and to make such dataavailable at a location more or less remote from the desks 300themselves. According to preferred embodiments of the present invention,the desk management system may be arranged to interpret those data andto make certain data available to a user via the display screen 345 toenable desk management decisions to be made in respect of particulardesks 300 or groups of desks 300. For example, the desk managementcomputer 340 may store or may have access to a database recording across-reference between pre-allocated desk identifiers (marked in avisually prominent position on the desks 300 themselves) and PSUidentifiers (235) of the respective PSUs 200 mounted therein. On receiptby wireless telemetry (350) of an indication that a particular PSUbattery pack 205 needs charging, desk management computer may identifythe desk 300 containing the particular PSU 200 by reference to thedatabase of cross-references, displaying the desk identifier on thedisplay 345 so that someone may be dispatched to locate the desk 300 andto connect the PSU 200 to a mains supply for recharging.

More advanced desk management facilities may also be provided, as willbe described further below. In particular, the desk management computer340 may also store or have access to a database recording across-reference between the LAN address of each wireless LAN interface315 connected to PCs 305 mounted within identified desks 300 so that, onreceipt for example of a low battery charge warning from a particularPSU 200, the desk management computer 340 may identify the desk 300 andhence the corresponding LAN address to enable a message to be sent tothe PC 305 at that LAN address, if the PC is being used at the time, fordisplay on the desk's flat panel display, warning the desk's currentuser of an impending loss of power in the desk 300.

There will now be described, with reference to FIG. 4, some preferredaspects of a desk management system 335 for use in monitoring andmanaging tetherless desks equipped with battery PSUs 200 described abovewith reference to FIG. 2. However, while the desk management system willbe described in the context of a separate computer 340, the functions ofthe desk management computer 340 may alternatively be implemented on theLAN server 330 and the desk management system user interface madeaccessible from selected terminal equipment linked to the LAN 320.

Referring to FIG. 4, a diagram is provided showing the functionalfeatures of a preferred desk management computer 340 for use in managinga number of tetherless desks 300 with PSUs 200 installed therein. Inthis particular embodiment, the desk management computer 340 is shownlinked to the LAN 320 by means of a LAN interface 410, although the deskmanagement computer 340 may also operate in a stand-alone arrangement ifrequired. The desk management computer 340 comprises: a wirelesstelemetry transmitter/receiver 415 for receiving transmissions ofdiagnostic parameter data from PSUs 200 (note that the wirelesstelemetry transmitter/receiver may alternatively be externally provided,as shown—350—in FIG. 3); a desk/PSU monitor 420 for carrying out initialprocessing of telemetry signals received via the wireless telemetryreceiver 415, for example time-stamping received data and convertingthose data into PSU-specific parameter records; a desk/PSU managementcontrol module 425 to implement the principal PSU/desk managementfunctions of the desk management computer 340; a user interface 430 toprovide user-access to the desk management functions; and a store 435 oraccess to a store, for example store 440 on LAN server 330, for holdinga database relating to PSUs 200, desks 300 and, if required, LANinterfaces 315 deployed in desks 300 and users of those desks 300. Alsoshown in FIG. 4 is the wireless LAN interface 325 providing acommunications path to a user of a tetherless desk 300 via the LAN 320and a PC 305 mounted within the desk 300.

In operation, a number of different desk management functions may beprovided by the desk management computer 340 for the benefit of a userresponsible for ensuring trouble-free operation of a number oftetherless desks 300 as part of a flexible office arrangement. Apreferred set of desk management functions, to be described in outlinebelow, are based upon a combination of predetermined data, preferablyrecorded in a database (435, 440) stored within or accessible to thecomputer 340, and diagnostic parameter data received from PSUs 200installed in the desks 300 to be managed. Output from particular deskmanagement functions provided by the desk management computer 340 mayalso be made available to current users of desks insofar as it isrelevant to operation of those specific desks. Such output may becommunicated to specific desks currently in use by means of the wirelessLAN.

In a preferred flexible office arrangement, for example that shown inFIG. 3, each tetherless desk 300 is provided with a PSU 200 as describedabove, and a PC 305 with a wireless LAN interface 315 connected to it.To each tetherless desk 300 is assigned a identifier, unique within theflexible office arrangement being managed. The identifier assigned toeach desk 300 is stored in a database (435, 440) and physically printedon the respective desk 300 in a visible position. To each PSU 200installed within desks 300 is assigned an identifier, unique among PSUs200 used in the flexible office arrangement being managed. Each PSUidentifier is stored both in the PSU 200 itself, in a store 235, and inthe database (435, 440). In the database (435, 440), the assigned deskidentifiers are cross-referenced to the corresponding assigned PSUidentifiers. Facilities are provided by means of the user interface 430to edit the records of PSU and desk identifiers as required.

At predetermined time intervals, each PSU 200 is arranged to transmitdiagnostic parameter data available at the diagnostics interface 225,via the wireless telemetry equipment 250, 415, to the desk managementcomputer 340. Each transmission of diagnostic data includes therespective PSU identifier (235) read by the PSU 200 from its store 235.Preferably, on receipt of a telemetry message, the desk/PSU monitor 420creates a diagnostic record of the received diagnostics parameters andwrites the time of receipt in each diagnostic record. The diagnosticrecords are passed to the desk/PSU management control module 425 to bestored in the store 435, 440 or processed in real time according to thedesk management functions implemented in the computer 340.

In addition to recording details of desk identifiers and PSUidentifiers, the database (435, 440) may also store details of LAN or IPaddresses assigned to the wireless LAN interfaces 315 connected to PCs305 in desks 300. A cross-reference between wireless LAN interfaceaddress and the respective desk identifier is also be recorded in thedatabase (435, 440). Such records may also be edited by means of theuser interface 430.

Further, the database (435, 440) may store details of user identifiersfor users known to be using, or with a history of using tetherless desks300 of the flexible office arrangement being managed. Preferably, thecontrol module 425 may capture user identifiers when users log onto theLAN server 330. In this way, the particular desk 300 being used may beidentified from the recorded cross-reference between the LAN or IPaddress of the wireless LAN interface 315 being used and a deskidentifier. Having identified a particular user, the control module 425may be associate any diagnostic parameter data gathered from therespective PSU 200 with that particular user and may keep a log of thatuser's demands upon the PSU 200 and other communications facilitiesprovided by the desk 300.

In particular, the control module 425 is arranged to maintain a log 426of the daily usage of each tetherless desk 300 identified in thedatabase (435, 440). Use may include the number of hours of use (usebeing detected by user log-on/logoff records and by current suppliedfrom the PSU 200), mean power consumed as calculated from diagnosticdata providing voltage and current supplied by the respective PSU 200,and recharging times when the desk 300 is plugged in for recharging(220). If available, user details may also be recorded in the log. Fromthis log data, numerous desk management functions may be implemented bythe control module 425 for the benefit of users via the user interface.For example, the following set of information may be offered, preferablyfrom a menu of options at the user interface 430 to generate workstationoperational status reports 427 and/or predictions 428 relating toworkstation operational status:

current battery charge level of each desk;

report of current status of a selected desk for all available diagnosticand user parameters;

use statistics for each selected desks;

report on expected battery life for each desk/PSU, including a warningas battery replacements become necessary;

schedule of recharging requirements for desks being managed, listingthose desks (by their identifiers) needing to be plugged in forrecharging at the end of the current day;

projected availability of power for a particular desk/PSU on the basisof use since the last recharge, optionally taking account of theparticular user or users using the desk and their historical usageprofiles;

recommendations for use of a particular identified desk according to theprojected requirements of an identified user who has reserved a desk fora specified period of time. Recommendation may be based upon the knowncurrent battery charge levels of those desks available for use, thefacilities offered by a particular desk (some desks may be more or lessequipped and may have different sized batteries in their PSUs).

This set of information facilities is provided by way of example only. Askilled person aware of the data available within the desk managementcomputer 340 would be able to devise further uses for that data,including further types of analysis to yield information useful for themanagement of tetherless desks.

There will now be described a further embodiment of the presentinvention having means to determine the physical location of tetherlessdesks 300 within an office space. Such a facility may be particularlyuseful where a large number of desks are deployed within an officespace, all being moveable to any position within that space. Finding aparticular desk identified as requiring attention by the desk managementcomputer 340 may be less than easy if only the desk identifier is known.

It will be clear that there are a number of ways in which a particulardesk can be located. A simple facility may be provided comprising aflashing light, mounted in a prominent position on a desk 300 and linkedby a cable to a PSU 200 mounted in that desk 300. The flashing light maybe triggered by a telemetry signal transmitted by the desk managementsystem, identifying the PSU 200 by its assigned identifier, thetelemetry signal being received at the PSU 200 telemetrytransmitter/receiver 250 and, if the PSU identifier matches that storedin the store 235, the PSU 200 triggers the flashing light, making thedesk clearly identifiable.

An alternative solution may be implemented using Bluetooth™ wirelesstechnology, as described in documents accessible for example of theworldwide web. Bluetooth wireless devices having a range of about 10meters are placed in the ceiling of an office space at, say, 5 meterintervals (one per 25 m² area), for use in locating desks and/or theirPSUs 200 also carrying Bluetooth devices. Each ceiling-mounted Bluetoothdevice acts as a passive responder to received inquiry packets sent outby PSU or desk-mounted Bluetooth devices operating as “masters”. Inquirypackets are only received by ceiling-mounted devices within range of thedesk/PSU-mounted masters, also selected as having a 10 metertransmitting range. The ceiling devices would return their pre-allocateddevice addresses (BD_ADDR) in inquiry reply FHS packets. The database(435, 440) of the desk management computer 340 contains a record of thephysical location (according to a predetermined office space locationsscheme) of each ceiling-mounted Bluetooth device and its correspondingdevice address (BD_ADDR). The database (435, 440) also contains a recordof the device address of each Bluetooth device mounted in a desk and/ora PSU 200 together with a cross-reference between the device address andthe corresponding desk/PSU identifier. Once a desk/PSU-mounted Bluetoothdevice receives the address of one or more ceiling-mounted Bluetoothdevices within range, that/those addresses are forwarded to the deskmanagement computer 340 for example by means of a Bluetooth pagingmessage to a Bluetooth device associated with the desk managementcomputer 340, or via one of the other wireless signaling routes providedfrom the desk 300—wireless telemetry in respect of a PSU-mountedBluetooth device, or the wireless LAN in respect of a device linked tothe PC 305 mounted within the desk 300.

In this way, the physical location of any desk may be determined by thedesk management computer 340, to a 5 to 10 meter resolution according tothe range of bluetooth devices used, by looking up the physical locationof the ceiling-mounted device whose address was returned in the latestmessage from a bluetooth device mounted the desk 300 or its PSU 200. Inthe event that a diagnostic data message received from a particular PSU200 indicates that its desk needs attention, the latest bluetoothlocation data for that desk 300 or PSU 200 may be easily consulted andmade available at the user interface 430.

Further variations on a bluetooth implementation of a desk/PSU locationsystem may be readily devised while remaining within the scope of thepresent patent application.

In respect of the PSU 200 and the desk management computer 340, it willbe clear to a skilled person in the art that various functional featuresmay be moved from the desk management system to the PSU 200, for examplemeans for storing identifiers other that the PSU identifier (235) and astore for storing log data relating to use of the PSU 200.

1. A battery power supply, said power supply comprising: a battery packinside a power supply housing; an inlet external to the housing for anexternally supplied charging current to terminals of said battery pack;a store for storing a unique identifier for said battery power supply; adiagnostics interface arranged to monitor and to output at least anindication of the level of charge in said battery pack and said uniqueidentifier stored in said store; and a wireless communications interfacefor transmitting said output from said diagnostics interface to anexternal monitoring apparatus.
 2. A battery power supply in claim 1,wherein said diagnostics interface is arranged to monitor and to outputan indication of electrical current being output from said battery pack.3. A battery power supply in claim 1 wherein said wirelesscommunications interface comprises a wireless telemetry transmitter. 4.A tetherless workstation having installed therein a battery power supplyas in claim 1 for supplying electrical power to equipment associatedwith said tetherless workstation.
 5. A monitoring apparatus, formonitoring a plurality of battery power supplies as in claim 1, saidmonitoring apparatus comprising, in combination with said plural batterypower supplies: a wireless communications interface for receivingsignals output from the diagnostics interface of a battery power supplyvia its wireless communications interface; and means, responsive to datareceived at said wireless communications interface, to generate reportsrelating to the operational status of said plurality of battery powersupplies.
 6. Apparatus as in claim 5, including means for determininguse of a battery power supply wherein said diagnostics interface isarranged to monitor and to output an indication of electrical currentbeing output from said battery pack and for storing a log of said use ina store.
 7. Apparatus as in claim 5, including analysis means foranalyzing data received at said wireless communications interface andfor generating predictions relating to the operational status of saidplurality of battery power supplies.
 8. A battery power supplycomprising: a battery pack; an inverter for converting electrical outputfrom said battery pack into a mains voltage electrical source; an inletfor an externally supplied charging current; a store for storing aunique identifier for said battery power supply; a diagnostics interfacearranged to monitor and to output at least an indication of the level ofcharge in said battery pack, and to output said unique identifier storedin said store; and a wireless communications interface for transmittingan output from said diagnostics interface.
 9. An apparatus, formonitoring a plurality of tetherless workstations having installedtherein a battery power supply for supplying electrical power toequipment associated with the tetherless workstation and including abattery pack; an inlet for an externally supplied charging current; astore for storing a unique identifier for said battery power supply; adiagnostics interface arranged to monitor and to output at least anindication of the level of charge in said battery pack and said uniqueidentifier stored in said store; and a wireless communications interfacefor transmitting an output from said diagnostics interface, saidapparatus for monitoring comprising: a wireless communications interfacefor receiving signals output from the diagnostics interface of a batterypower supply; a store for storing, in respect of each of said pluralityof tetherless workstations, a unique workstation identifier and theunique identifier of a battery power supply installed therein; andmeans, responsive to data received at said wireless communicationsinterface and to data stored in said store, for generating reportsrelating to the operational status of said tetherless workstations. 10.An apparatus as in claim 9, including means for storing a usage log inrespect of at least one of said workstations.
 11. An apparatus as inclaim 10, including analysis means for analyzing data received at saidwireless communications interface and data stored in said usage log andfor generating predictions relating to the operational status of saidtetherless workstations.
 12. Apparatus as in claim 10, including meansfor identifying users of said tetherless workstations, and wherein saidusage log includes data identifying respective users.
 13. Apparatus asin claim 12, wherein said analysis means is arranged to generatepredictions relating to the operational status of at least one of saidworkstations in respect of a particular user.
 14. A flexible officearrangement comprising a plurality of tetherless workstations havinginstalled therein a battery power supply for supplying electrical powerto equipment associated with the tetherless workstation and including abattery pack; an inlet for an externally supplied charging current; astore for storing a unique identifier for said battery power supply; adiagnostics interface arranged to monitor and to output at least anindication of the level of charge in said battery pack, and to outputsaid unique identifier stored in said store; and a wirelesscommunications interface for transmitting an output from saiddiagnostics interface; said apparatus for monitoring said plurality ofworkstations comprising: a wireless communications interface forreceiving signals output from the diagnostics interface of a batterypower supply; a store for storing, in respect of each of said pluralityof tetherless workstations, a unique workstation identifier and theunique identifier of a battery power supply installed therein; andmeans, responsive to data received at said wireless communicationsinterface and to data stored in said store, for generating reportsrelating to the operational status of said tetherless workstations.